tools/bugpoint/BugDriver.cpp

   1 //===- BugDriver.cpp - Top-Level BugPoint class implementation ------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This class contains all of the shared state and information that is used by
  11 // the BugPoint tool to track down errors in optimizations.  This class is the
  12 // main driver class that invokes all sub-functionality.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "BugDriver.h"
  17 #include "ToolRunner.h"
  18 #include "llvm/Linker.h"
  19 #include "llvm/Module.h"
  20 #include "llvm/Pass.h"
  21 #include "llvm/Assembly/Parser.h"
  22 #include "llvm/Bitcode/ReaderWriter.h"
  23 #include "llvm/Support/CommandLine.h"
  24 #include "llvm/Support/FileUtilities.h"
  25 #include "llvm/Support/MemoryBuffer.h"
  26 #include "llvm/Support/SourceMgr.h"
  27 #include "llvm/Support/raw_ostream.h"
  28 #include <memory>
  29 using namespace llvm;
  30
  31 // Anonymous namespace to define command line options for debugging.
  32 //
  33 namespace {
  34   // Output - The user can specify a file containing the expected output of the
  35   // program.  If this filename is set, it is used as the reference diff source,
  36   // otherwise the raw input run through an interpreter is used as the reference
  37   // source.
  38   //
  39   cl::opt<std::string>
  40   OutputFile("output", cl::desc("Specify a reference program output "
  41                                 "(for miscompilation detection)"));
  42 }
  43
  44 /// setNewProgram - If we reduce or update the program somehow, call this method
  45 /// to update bugdriver with it.  This deletes the old module and sets the
  46 /// specified one as the current program.
  47 void BugDriver::setNewProgram(Module *M) {
  48   delete Program;
  49   Program = M;
  50 }
  51
  52
  53 /// getPassesString - Turn a list of passes into a string which indicates the
  54 /// command line options that must be passed to add the passes.
  55 ///
  56 std::string llvm::getPassesString(const std::vector<const PassInfo*> &Passes) {
  57   std::string Result;
  58   for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
  59     if (i) Result += " ";
  60     Result += "-";
  61     Result += Passes[i]->getPassArgument();
  62   }
  63   return Result;
  64 }
  65
  66 BugDriver::BugDriver(const char *toolname, bool as_child, bool find_bugs,
  67                      unsigned timeout, unsigned memlimit,
  68                      LLVMContext& ctxt)
  69   : Context(ctxt), ToolName(toolname), ReferenceOutputFile(OutputFile),
  70     Program(0), Interpreter(0), SafeInterpreter(0), gcc(0),
  71     run_as_child(as_child), run_find_bugs(find_bugs), Timeout(timeout),
  72     MemoryLimit(memlimit)  {}
  73
  74
  75 /// ParseInputFile - Given a bitcode or assembly input filename, parse and
  76 /// return it, or return null if not possible.
  77 ///
  78 Module *llvm::ParseInputFile(const std::string &Filename,
  79                              LLVMContext& Ctxt) {
  80   std::auto_ptr<MemoryBuffer> Buffer(MemoryBuffer::getFileOrSTDIN(Filename));
  81   Module *Result = 0;
  82   if (Buffer.get())
  83     Result = ParseBitcodeFile(Buffer.get(), Ctxt);
  84
  85   SMDiagnostic Err;
  86   if (!Result && !(Result = ParseAssemblyFile(Filename, Err, Ctxt))) {
  87     Err.Print("bugpoint", errs());
  88     Result = 0;
  89   }
  90
  91   return Result;
  92 }
  93
  94 // This method takes the specified list of LLVM input files, attempts to load
  95 // them, either as assembly or bitcode, then link them together. It returns
  96 // true on failure (if, for example, an input bitcode file could not be
  97 // parsed), and false on success.
  98 //
  99 bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
 100   assert(Program == 0 && "Cannot call addSources multiple times!");
 101   assert(!Filenames.empty() && "Must specify at least on input filename!");
 102
 103   try {
 104     // Load the first input file.
 105     Program = ParseInputFile(Filenames[0], Context);
 106     if (Program == 0) return true;
 107
 108     if (!run_as_child)
 109       outs() << "Read input file      : '" << Filenames[0] << "'\n";
 110
 111     for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
 112       std::auto_ptr<Module> M(ParseInputFile(Filenames[i], Context));
 113       if (M.get() == 0) return true;
 114
 115       if (!run_as_child)
 116         outs() << "Linking in input file: '" << Filenames[i] << "'\n";
 117       std::string ErrorMessage;
 118       if (Linker::LinkModules(Program, M.get(), &ErrorMessage)) {
 119         errs() << ToolName << ": error linking in '" << Filenames[i] << "': "
 120                << ErrorMessage << '\n';
 121         return true;
 122       }
 123     }
 124   } catch (const std::string &Error) {
 125     errs() << ToolName << ": error reading input '" << Error << "'\n";
 126     return true;
 127   }
 128
 129   if (!run_as_child)
 130     outs() << "*** All input ok\n";
 131
 132   // All input files read successfully!
 133   return false;
 134 }
 135
 136
 137
 138 /// run - The top level method that is invoked after all of the instance
 139 /// variables are set up from command line arguments.
 140 ///
 141 bool BugDriver::run() {
 142   // The first thing to do is determine if we're running as a child. If we are,
 143   // then what to do is very narrow. This form of invocation is only called
 144   // from the runPasses method to actually run those passes in a child process.
 145   if (run_as_child) {
 146     // Execute the passes
 147     return runPassesAsChild(PassesToRun);
 148   }
 149
 150   if (run_find_bugs) {
 151     // Rearrange the passes and apply them to the program. Repeat this process
 152     // until the user kills the program or we find a bug.
 153     return runManyPasses(PassesToRun);
 154   }
 155
 156   // If we're not running as a child, the first thing that we must do is
 157   // determine what the problem is. Does the optimization series crash the
 158   // compiler, or does it produce illegal code?  We make the top-level
 159   // decision by trying to run all of the passes on the the input program,
 160   // which should generate a bitcode file.  If it does generate a bitcode
 161   // file, then we know the compiler didn't crash, so try to diagnose a
 162   // miscompilation.
 163   if (!PassesToRun.empty()) {
 164     outs() << "Running selected passes on program to test for crash: ";
 165     if (runPasses(PassesToRun))
 166       return debugOptimizerCrash();
 167   }
 168
 169   // Set up the execution environment, selecting a method to run LLVM bitcode.
 170   if (initializeExecutionEnvironment()) return true;
 171
 172   // Test to see if we have a code generator crash.
 173   outs() << "Running the code generator to test for a crash: ";
 174   try {
 175     compileProgram(Program);
 176     outs() << '\n';
 177   } catch (ToolExecutionError &TEE) {
 178     outs() << TEE.what();
 179     return debugCodeGeneratorCrash();
 180   }
 181
 182
 183   // Run the raw input to see where we are coming from.  If a reference output
 184   // was specified, make sure that the raw output matches it.  If not, it's a
 185   // problem in the front-end or the code generator.
 186   //
 187   bool CreatedOutput = false;
 188   if (ReferenceOutputFile.empty()) {
 189     outs() << "Generating reference output from raw program: ";
 190     if(!createReferenceFile(Program)){
 191       return debugCodeGeneratorCrash();
 192     }
 193     CreatedOutput = true;
 194   }
 195
 196   // Make sure the reference output file gets deleted on exit from this
 197   // function, if appropriate.
 198   sys::Path ROF(ReferenceOutputFile);
 199   FileRemover RemoverInstance(ROF, CreatedOutput);
 200
 201   // Diff the output of the raw program against the reference output.  If it
 202   // matches, then we assume there is a miscompilation bug and try to
 203   // diagnose it.
 204   outs() << "*** Checking the code generator...\n";
 205   try {
 206     if (!diffProgram()) {
 207       outs() << "\n*** Output matches: Debugging miscompilation!\n";
 208       return debugMiscompilation();
 209     }
 210   } catch (ToolExecutionError &TEE) {
 211     errs() << TEE.what();
 212     return debugCodeGeneratorCrash();
 213   }
 214
 215   outs() << "\n*** Input program does not match reference diff!\n";
 216   outs() << "Debugging code generator problem!\n";
 217   try {
 218     return debugCodeGenerator();
 219   } catch (ToolExecutionError &TEE) {
 220     errs() << TEE.what();
 221     return debugCodeGeneratorCrash();
 222   }
 223 }
 224
 225 void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
 226   unsigned NumPrint = Funcs.size();
 227   if (NumPrint > 10) NumPrint = 10;
 228   for (unsigned i = 0; i != NumPrint; ++i)
 229     outs() << " " << Funcs[i]->getName();
 230   if (NumPrint < Funcs.size())
 231     outs() << "... <" << Funcs.size() << " total>";
 232   outs().flush();
 233 }
 234
 235 void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs) {
 236   unsigned NumPrint = GVs.size();
 237   if (NumPrint > 10) NumPrint = 10;
 238   for (unsigned i = 0; i != NumPrint; ++i)
 239     outs() << " " << GVs[i]->getName();
 240   if (NumPrint < GVs.size())
 241     outs() << "... <" << GVs.size() << " total>";
 242   outs().flush();
 243 }